Preparation and culture of a serum-free human thyroid follicle system and its application for measuring thyroid hormone secretion, iodide uptake and organification, cyclic adenosine monophosphate formation, gene expression, and cell growth

We describe a system of human thyroid follicles cultured in collagen suspen ded in serum-free medium. The method allows measurement of thyroid hormone secretion, iodide uptake and organification, cyclic adenosine monophosphate (cAMP) formation, gene expression, as well as cell growth. The system is s uperior to follicles freely suspended in cultured medium and also, as demon strated by parallel experiments, to monolayer culture systems. A detailed d escription of the optimal conditions of the method is provided that, over a period of 8 years, has proven to be a powerful tool for measuring thyroid cell function, gene expression and cell proliferation.